1. Field of the Invention
The present invention relates to an insecticidal composition of Cypermethrin and Acephate with enhanced synergistic insecticidal activity and a process to prepare the same.
2. Description of Related Art
The protection of crops and its produce from insect pest damage is essential in agriculture produce enhancement. To help combat these problems, various chemicals and formulations were invented for effective management of pests. Insecticides of many types and groups are reported in the literature and a large number are in use, commercially, for effective control of pests in agriculture.
In many cases, active insecticides have shown more effectiveness in combination than when applied individually. Synergism occurs when a combination demonstrates a potency and activity level exceeding that, which might be expected, from a mere addition of the individual potencies of the components.
In modern agricultural scenarios, insects have attained resistance, due to indiscriminate and non-judicious use of pesticide. Potent synergistic insecticidal composition would by useful to manage insect pests for a desired higher crop yield and to control those insects which are hard to kill by existing commercial insecticides solely and in cyclic spray mixtures.
Cypermethrin is presently recognized as a non-systemic insecticide with contact and stomach action. It also exhibits anti-feeding action and good residual activity on treated plants. It is used to control a wide range of insects, especially Lepidoptera, but also Coleoptera, Deptera, Hemiptera and other classes in fruits (including Citrus), Vines, Vegetables, Potatoes, Cucurbits, Lettuce, Capsicums, tomatoes, cereals, maize, soybeans, cotton, coffee, cocoa, rice, pecans, oilseeds rape, beet, ornamentals, forestry, etc. It is also used for control of flies, and other insects in animal houses, mosquitoes, cockroaches, houseflies and other insect pests in public. It is also used as an animal ectoparasiticide.
Presently Cypermethrin is most preferably formulated in the form of emulsifiable concentrate (EC) which consists of Cypermethrin active ingredients dissolved in solvent(s) along with surfactants at levels required to give maximum stability with the formation of a homogeneous emulsion on dilution. The use of organic solvent(s) is disadvantageous from an environmental and cost view point. These organic solvents exhibit toxicity and side-effects which may be adverse to the effect of the agricultural chemical itself or to the plant or crop as a whole or to its parts produced in treated fields. They show hazards during manufacturing, filling, packing, storage, transit and use. During use, dermal and respiratory toxic exposure to users is frequently observed. By using the organic solvents percutaneous toxicity and inflammability may also occur.
The formulation of Acephate presently in use is Acephate 75% Soluble Powder (SP) which consists of Acephate active ingredient 75% (w/w), surfactant 1% to 2% (w/w) and inert filler (Precipitated Silica) to make 100% (w/w). It poses problems like dust, low pourability, high transportation cost, and high capital manufacturing investment. This formulation is not easily measurable, presents difficulties in packing material disposal, produces handling problems, and poses a high risk of caking along with other problems.
Both of these compounds are capable of controlling a large spectrum of insects especially Lepidoptera, Coleoptra, Diptera, Hemiptera and others in classes such as fruits, vegetables, ornamentals, etc. Cypermethrin is distinguished for its sudden shock effect along with good residual activity on treated plants. Acephate is a systemic insecticide of moderate persistence with residual activity and thrips. It is phytotoxic on many crop plants.
A mixture of organophosphates and pyrethroids have been reported in literature, but these are applied as separate sprays or tank mixes. Formulations containing both are not reported.